Materials Data on La21Fe8Sn7C12 by Materials Project

Abstract

La21Fe8Sn7C12 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are three inequivalent La sites. In the first La site, La is bonded to three equivalent Sn and three equivalent C atoms to form distorted LaSn3C3 octahedra that share corners with six equivalent LaSn3C3 octahedra, edges with three equivalent LaSn3C3 octahedra, and a faceface with one LaSn6 octahedra. The corner-sharing octahedra tilt angles range from 18–43°. All La–Sn bond lengths are 3.39 Å. All La–C bond lengths are 2.70 Å. In the second La site, La is bonded in a distorted L-shaped geometry to three Sn and two equivalent C atoms. There are two shorter (3.42 Å) and one longer (3.96 Å) La–Sn bond lengths. Both La–C bond lengths are 2.60 Å. In the third La site, La is bonded to six equivalent Sn atoms to form face-sharing LaSn6 octahedra. All La–Sn bond lengths are 3.47 Å. Fe is bonded in a trigonal planar geometry to three equivalent C atoms. All Fe–C bond lengths are 1.89 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 9-coordinate geometry to nine La atoms. In the second Sn site, Sn is bonded to twelve equivalent La atoms to form SnLa12 cuboctahedra that share corners with twenty-four equivalent CLa4Fe2 octahedra. The corner-sharing octahedral tilt angles are 44°. C is bonded to four La and two equivalent Fe atoms to form distorted CLa4Fe2 octahedra that share corners with two equivalent SnLa12 cuboctahedra and edges with five equivalent CLa4Fe2 octahedra.